Voice authentication systems are becoming increasingly popular for providing access control. For example, voice authentication systems are currently being utilised in telephone banking systems, automatic teller machines, building or office entry access system, etc.
Voice authentication is typically conducted over a fixed telephone network (e.g. a PSTN telecommunications network) as a two stage process. The first stage, or enrollment stage, involves storing a sample of a person's voice to extract and encode their unique voice characteristics. The second stage, or authentication stage, involves receiving a voice sample of a person to be identified over the phone and comparing the voice characteristics of the received sample with those of the stored voice sample, using a voice authentication engine. A measure as to how closely the voice sample of the person to be identified compares to the stored voice sample (and therefore the likelihood that the person is, in fact, the same as that being claimed) is then outputted by the voice authentication engine.
A problem with such voice authentication systems is that they require significant infrastructure expense on the part of the secure service provider and there is also expense incurred by users of the system in placing the calls. Furthermore, persons who do not have access to a phone line are unable to participate.